1. Field of the Invention
The present invention relates generally to a drive wrench and fastener combination and, more particularly, to a drive wrench and fastener combination which employs an axial guide pin and a plurality of coded key elements disposed in a socket which mate with a corresponding recess and lock impressions disposed in the fastener.
2. Description of the Prior Art
Heretofore, numerous drive wrenches and screwdrivers have been designed to assist in installing and removing fasteners of various kinds for use in various applications. A variety of these configurations are shown in U.S. Pat. No. 3,878,740 issued to Charles E. Gutshall, entitled Wrench Socket Assembly; U.S. Pat. No. 3,449,988 issued to J. Gallo, Sr., entitled Speed Tool With Guide Pin; U.S. Pat. No. 4,242,932 issued to Thomas C. Barmore, entitled Fastening Device; U.S. Pat. No. 3,279,838 issued to Douglas Hamilton, entitled Locking Securement For Sheet Metal Housing Cover; U.S. Pat. No. 4,109,691 issued to Floyd Wilson, entitled Combination Torque Release Screw and Screwdriver; and French Pat. No. 1.196.287 issued to M. Monticelli.
The Gutshall patent discloses a socket wrench which is used to tighten a torque limited fastener that is kept from wobbling on the head of the fastener during tightening. This socket wrench is designed for use with hex head type screws or bolts with weakened corners. The socket is designed to slip around the weakened corner once the desired torque is applied. The socket is kept from wobbling by a pressed-in insert which includes a projection which may be inserted into a recess in the head of the screw.
The Gallo patent discloses a speed wrench or screwdriver which employs a protruding guide pin that inserts into a hole in the fastener for the purpose of locating the fastener on the wrench. A plurality of externally located key elements or fingers in the socket are inserted into a matching plurality of eccentric apertures in the fastener which secure the tool to the fastener during operation.
The Barmore patent discloses a tool for use with a hex head or similar type fastener having a specially broached hole therein. The tool includes a protruding pin which is used as an auxiliary drive member that engages the specially broached hole to permit better engagement between the tool and fastener as more torque is applied.
The Hamilton patent shows a fastener employing a socket head arrangement with a projecting prong which prevents the use of a standard Allen key for installation or removal. The prong allows a special tool, such as a modified Allen key to be used to remove the fastener.
The Wilson patent discloses a screwdriver which has an axial projection to assist the tool in engaging a specially designed torque-limited screw. The tool has specially designed cam projections which engage lugs on the screw. The lugs break off once the desired torque is reached.
The Monticelli patent seems to show a tool having a spring loaded pin and a plurality of external key elements or fingers utilized for engaging some type of fastener or similar device.
These patents disclose a wide variety of wrench and fastener combinations. Some of the wrenches employ an axially located pin which may be employed to prevent wobbling or which is generally used to assist in locating the fastener in or on the wrench. However, none of these patents disclose wrenches which may be readily employed with round or cylindrically headed screws or bolts. In addition, none of the patents disclose the use of rounded or beveled key elements on the inner periphery of a socket which, when placed in contact with the bolt and in conjunction with an axial pin, assist in mating the wrench with the fastener. None of the patents disclose a wrench and fastener combination that employs axially oriented lock impressions on the outer periphery of the head of the bolt and corresponding key elements on the inner periphery of the socket head. In addition, none of the patents disclose the use of a screwdriver-like handle arrangement which may be employed to remove covers or caps or the like covering the fastener which is to be removed.
There is also known in the prior art a fastener and wrench combination which employs a plurality of axially slotted lock impressions disposed on the periphery of the fastener head and a corresponding plurality of key elements disposed on the inner periphery of the socket which allow for a coded key/lock wrench combination. That combination has proven, however, to present certain difficulties in mounting the wrench on the fastener head, particularly when such must be done in the dark or under other trying circumstances such as in the rain, alongside a road in heavy traffic, and the like.
It is therefore an object of the present invention to provide a combination wrench and fastener which permits entrance of the fastener head into the wrench socket prior to key/lock engagement so that the two members of the combination may be guided in alignment while the socket is being rotated into a position where the keys and lock impressions mate, and which further stabilizes the wrench on the fastener while tightening or untightening the fastener.
It is also an object of the present invention to provide a wrench which includes a transversely affixed handle that has a prying tip or tool disposed on at least one end thereof which may be employed to remove a protective cap covering the fastener to be removed or installed.